I guess digital downloads will eventually kill all the physical discs, sooner or later, with the sudden changes happening now, I will not be surprised if it happens earlier than expected. DVD did not killed VCD totally, maybe because VCD to DVD is still a physical to physical technology, unlike DL's, aside it from being cheaper (like the sites mentioned by NeoXorn), whichever is more convenient is what people will patronize. Imagine getting a movie with just a click away. In connection, Disney Stores are also closing down and will settle for on-line purchases, this are the changes that we have to live with.
But with the emerging DL sites nowadays, I can't seem to imagine how Warner or other companies will battle this competetion. FREE vs cheap, now where would you go?
Sad..yes. Definitely a change that will be very hard for some, I for one is a physical collector, I like seeing my collection, my holy grail. However, someday somehow I will be forced to bite to the changes.